For copying data to/from cloud providers there is rclone [1]. This can copy from Google Drive, but for Google Photos it supports downloading files only at reduced (rather than original) resolution [2].

For backing up email, there is mbsync [3].

[1]: https://rclone.org/

[2]: https://rclone.org/googlephotos/#downloading-images

[3]: https://linux.die.net/man/1/mbsync